var mysql = require("mysql");

var pool = mysql.createPool({
  host: '47.90.157.187',
  user: 'root',
  password: 'Earnplaycenter123.',
  database: 'face-recognition',
  port: 3306
});

//callback为回调方法
async function queryDataBySQL(sql, callback) {
  return await new Promise((reslove, reject) => {
    pool.getConnection(function (err, connection) {
      connection.query(sql, function (err, result) {
        if (err) { reject(err) } else {
          if (callback) {
            callback(result)
          }
          reslove(result)
        }

      });
      connection.release();
      //console.log("close mysql connection");
    });
  })
};

module.exports = {
  queryDataBySQL
}